From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE6F2C433DF for ; Fri, 5 Jun 2020 12:58:48 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 784D5206A2 for ; Fri, 5 Jun 2020 12:58:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TW4+52tn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 784D5206A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9eZWgrwCLNeDT8WBOVNTLpqMSTjuBq9w0HLVXgMdwSs=; b=TW4+52tnepGNh5J7tN4GHoG9N ai1nNdMaZeGldiTdNhUtvMpymkSGCESVcgH0cFg4Yo+lGIRXKNxnVq8g1bjmLCSFq+2lEPIVOeHq3 m8wjhXYWEIE2O0gLrRAPf4E7XHEGadyogJswA9ELj+tIQcSB951diwbro6NnoB/Y0gtzFYeLb1y2v ETNYWZoC3VwopsCtkSqkygVvsrTkFEmM9qO+++VdnN8DtNyyYXM8OXgRxcXGGpLRLTRYdipuQnXc5 K3beetm304o1QpHgQexoyBv65l/YrA7BxdjjDlxWi0hgvahfgyDJzjQb5GsszdGKsa6P7jDX3ZDIT cW9C6ywhQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jhBvr-00043l-Qi; Fri, 05 Jun 2020 12:58:47 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jhBvn-00042t-Td for linux-arm-kernel@lists.infradead.org; Fri, 05 Jun 2020 12:58:45 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BCABA31B; Fri, 5 Jun 2020 05:58:42 -0700 (PDT) Received: from [10.57.10.23] (unknown [10.57.10.23]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 40DF63F305; Fri, 5 Jun 2020 05:58:40 -0700 (PDT) Subject: Re: Please help to confirm the risk if using TPIDRRO_EL0 to save CPU number, thanks. To: Will Deacon , Mark Brown References: <1D289F1E6D91D2489524BBB0B8880A7DA1A39219@dggeml509-mbx.china.huawei.com> <20200601070311.GA8601@willie-the-truck> <20200605121029.GE5413@sirena.org.uk> <20200605123302.GA19936@willie-the-truck> From: Robin Murphy Message-ID: Date: Fri, 5 Jun 2020 13:58:39 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200605123302.GA19936@willie-the-truck> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200605_055844_036847_E9099E2F X-CRM114-Status: GOOD ( 20.04 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "fujun \(F\)" , Wuxuecheng , "Lixin \(Victor, Kirin\)" , "linux-arm-kernel@lists.infradead.org" Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; 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